Detcon IR-700 - Manual (Page 29)

Model IR-700
IR-700 Instruction Manual Rev. 3.1 Page 25 of 40
Zero Fault
If the sensor drifts below –10% LEL, the “Zero Fault” will be declared. A “Zero Fault” will cause a “Fault
Detected” message to scroll once a minute on the ITM display and drop the 4-20mA output to 0mA. The
Modbus™ fault register bit for Zero Fault will be set and will not clear until the fault condition has been
cleared.
The sensor should be considered “Out-of-Service” until a successful AutoZero calibration is
performed.
Range Fault – AutoSpan
If the sensor fails the minimum signal change criteria during AutoSpan sequence (Section 3.4.2) the “Range
Fault” will be declared. A “Range Fault” will cause a “Fault Detected” message to scroll once a minute on the
ITM display and drop the 4-20mA output to 0mA. The Modbus™ fault register bit for Range Fault will be set
and will not clear until the fault condition has been cleared. The sensor should be considered “Out-of-Service”
until a successful AutoSpan calibration is performed.
Stability Fault – AutoSpan
If the sensor fails the signal stability criteria during AutoSpan sequence (Section 3.4.2) the “Stability Fault”
will be declared. A “Stability Fault” will cause a “Fault Detected” message to scroll once a minute on the ITM
display and drop the milliamp output to 0mA. The Modbus™ fault register bit for Stability Fault will be set
and will not clear until the fault condition has been cleared. The sensor should be considered as “Out-of-
Service” until a successful AutoSpan calibration is performed.
Clearing Fault – AutoSpan
If the sensor fails the signal stability criteria during AutoSpan sequence (Section 3.4.2) the “Clearing Fault”
will be declared. A “Clearing Fault” will cause a “Fault Detected” message to scroll once a minute on the
ITM display and drop the milliamp output to 0mA. The Modbus™ fault register bit for Clearing Fault will be
set and will not clear until the fault condition has been cleared. The sensor should be considered as “Out-of-
Service” until a successful AutoSpan calibration is performed.
Sensor Fault
If the plug-in IR sensor, or the supporting electronics, fails to meet the required minimum or maximum
working signal parameters a “Sensor Fault” will be declared. A “Sensor Fault” will cause a “Fault Detected”
message to scroll once a minute on the ITM display. The Modbus™ fault register bit for Sensor Fault will be
set and will not clear until the fault condition has been cleared. If a Sensor Fault occurs, the 4-20mA signal
will be set at 0mA until the fault condition is resolved.
Processor Fault
If the detector has any unrecoverable run-time errors, a “Processor Fault” is declared. A “Processor Fault”
will cause a “Fault Detected” message to scroll once a minute on the ITM display. The Modbus™ fault
register bit for Processor Fault will be set and will not clear until the fault condition has been cleared. If a
Processor Fault occurs, the 4-20mA signal will be set at 0mA until the fault condition is resolved.
Memory Fault
If the detector has a failure in saving new data to memory, a “Memory Fault” is declared. A “Memory Fault”
will cause the “Fault Detected” message to scroll once a minute on the ITM display. The Modbus™ fault
register bit for Memory Fault will be set and will not clear until the fault condition has been cleared. If a
Memory Fault occurs, the 4-20mA signal will be set at 0mA until the fault condition is resolved.